more use const for interface of libbb/compare_string_array, example usage for e2fsprogs/fsck
diff --git a/libbb/compare_string_array.c b/libbb/compare_string_array.c
index 993b462..8961e00 100644
--- a/libbb/compare_string_array.c
+++ b/libbb/compare_string_array.c
@@ -17,7 +17,8 @@
#include <string.h>
/* returns the array number of the string */
-extern unsigned short compare_string_array(const char *string_array[], const char *key)
+extern unsigned short
+compare_string_array(const char * const string_array[], const char *key)
{
unsigned short i;