Fix pointer increment bug

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2061 42af7a65-404d-4744-a932-0658087f49c3

lib/lib_strstr.c

@@ -54,7 +54,7 @@ char *strstr(const char *str, const char *substr)
   /* Special case the empty substring */
 
   len = strlen(substr);
-  ch  = *substr++;
+  ch  = *substr;
 
   if (!ch)
     {