Rename Strncat to StrnAppend, use it instead of strncat.

Strncat() looks almost like strncat(), but it's completely different. Change
the name to reduce confusion.

Also fix a place where strncat() was misused anyway.

BUG=none
BRANCH=all
TEST=manual

sudo FEATURES=test emerge vboot_reference
FEATURES=test emerge-$BOARD vboot_reference

Change-Id: I39c30d391aa6566ec67461462e800720ade66a91
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/44572
diff --git a/Makefile b/Makefile
index 49cdab5..a7101cc 100644
--- a/Makefile
+++ b/Makefile
@@ -331,6 +331,7 @@
 	utility/dump_kernel_config_lib.c \
 	firmware/lib/cgptlib/crc32.c \
 	firmware/lib/cgptlib/cgptlib_internal.c \
+	firmware/lib/utility_string.c \
 	firmware/stub/utility_stub.c
 
 TINYHOSTLIB_OBJS = ${TINYHOSTLIB_SRCS:%.c=${BUILD}/%.o}