partition_parser: Fixed return type error

Change partition_get_index() return type to int as on error
-1 is returned

Change-Id: Icb061a231e531d80091ca2dc1ba1e42f427bf7da
diff --git a/platform/msm_shared/partition_parser.c b/platform/msm_shared/partition_parser.c
index abb5d81..881d2a0 100644
--- a/platform/msm_shared/partition_parser.c
+++ b/platform/msm_shared/partition_parser.c
@@ -807,7 +807,7 @@
 /*
  * Find index of parition in array of partition entries
  */
-unsigned partition_get_index(const char *name)
+int partition_get_index(const char *name)
 {
 	unsigned int input_string_length = strlen(name);
 	unsigned n;