Key increment scripts: fix incrementing keys not in $PWD

Part of the recent rewrite dropped changing of the active dir to
${KEY_DIR}.  Meant the scripts needed to be run inside of the key
dir since not all functions take the key dir as an argument but
instead assume they're in ${PWD}.

BUG=None
TEST=Ran increment_kernel_subkey_and_key_mp.sh and saw it work
BRANCH=None

Change-Id: Icbc02f123e999d186d9c40fd16528a134397699e
Reviewed-on: https://gerrit.chromium.org/gerrit/35803
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/keygeneration/common.sh b/scripts/keygeneration/common.sh
index b7725ad..c3c1c25 100755
--- a/scripts/keygeneration/common.sh
+++ b/scripts/keygeneration/common.sh
@@ -125,6 +125,8 @@
 # Loads the current versions prints them to stdout and sets the global version
 # variables: CURR_FIRMKEY_VER CURR_FIRM_VER CURR_KERNKEY_VER CURR_KERN_VER
 load_current_versions() {
+  local key_dir=$1
+  local VERSION_FILE="${key_dir}/${VERSION_FILE}"
   if [[ ! -f ${VERSION_FILE} ]]; then
     return 1
   fi
diff --git a/scripts/keygeneration/increment_firmware_data_key.sh b/scripts/keygeneration/increment_firmware_data_key.sh
index facd776..c6b65a4 100755
--- a/scripts/keygeneration/increment_firmware_data_key.sh
+++ b/scripts/keygeneration/increment_firmware_data_key.sh
@@ -24,9 +24,10 @@
 KEY_DIR=$1
 
 main() {
-  load_current_versions
+  load_current_versions "${KEY_DIR}"
   new_firmkey_ver=$(increment_version "${KEY_DIR}" "firmware_key_version")
 
+  cd "${KEY_DIR}"
   backup_existing_firmware_keys ${CURR_FIRM_VER} ${CURR_FIRMKEY_VER}
 
   cat <<EOF
diff --git a/scripts/keygeneration/increment_kernel_data_key.sh b/scripts/keygeneration/increment_kernel_data_key.sh
index 193df2a..b3ed3ea 100755
--- a/scripts/keygeneration/increment_kernel_data_key.sh
+++ b/scripts/keygeneration/increment_kernel_data_key.sh
@@ -24,9 +24,10 @@
 KEY_DIR=$1
 
 main() {
-  load_current_versions
+  load_current_versions "${KEY_DIR}"
   new_kernkey_ver=$(increment_version "${KEY_DIR}" "kernel_key_version")
 
+  cd "${KEY_DIR}"
   backup_existing_kernel_data_keys ${CURR_FIRM_VER} ${CURR_KERNKEY_VER}
 
   cat <<EOF
diff --git a/scripts/keygeneration/increment_kernel_subkey.sh b/scripts/keygeneration/increment_kernel_subkey.sh
index b18847e..ccac937 100755
--- a/scripts/keygeneration/increment_kernel_subkey.sh
+++ b/scripts/keygeneration/increment_kernel_subkey.sh
@@ -24,9 +24,10 @@
 KEY_DIR=$1
 
 main() {
-  load_current_versions
+  load_current_versions "${KEY_DIR}"
   new_firm_ver=$(increment_version "${KEY_DIR}" "firmware_version")
 
+  cd "${KEY_DIR}"
   backup_existing_kernel_subkeys ${CURR_FIRM_VER} ${CURR_KERNKEY_VER}
 
   cat <<EOF
diff --git a/scripts/keygeneration/increment_kernel_subkey_and_key.sh b/scripts/keygeneration/increment_kernel_subkey_and_key.sh
index ac84660..dda0416 100755
--- a/scripts/keygeneration/increment_kernel_subkey_and_key.sh
+++ b/scripts/keygeneration/increment_kernel_subkey_and_key.sh
@@ -25,10 +25,11 @@
 KEY_DIR=$1
 
 main() {
-  load_current_versions
+  load_current_versions "${KEY_DIR}"
   new_kernkey_ver=$(increment_version "${KEY_DIR}" "kernel_key_version")
   new_firm_ver=$(increment_version "${KEY_DIR}" "firmware_version")
 
+  cd "${KEY_DIR}"
   backup_existing_kernel_subkeys ${CURR_FIRM_VER} ${CURR_KERNKEY_VER}
   backup_existing_kernel_data_keys ${CURR_FIRM_VER} ${CURR_KERNKEY_VER}