s/Tst_count/tst_count/ to avoid CamelCase

when using latest checkpatch.pl, CamelCase variables are not encouraged,
this patch does a batch update to replace all var `Tst_count` with
`tst_count`.

Signed-off-by: Caspar Zhang <caspar@casparzhang.com>
Acked-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
diff --git a/testcases/kernel/syscalls/stat/stat03.c b/testcases/kernel/syscalls/stat/stat03.c
index 9637de1..dfbe02e 100644
--- a/testcases/kernel/syscalls/stat/stat03.c
+++ b/testcases/kernel/syscalls/stat/stat03.c
@@ -164,7 +164,7 @@
 
 	for (lc = 0; TEST_LOOPING(lc); lc++) {
 
-		Tst_count = 0;
+		tst_count = 0;
 
 		for (ind = 0; Test_cases[ind].desc != NULL; ind++) {
 			file_name = Test_cases[ind].pathname;
@@ -203,7 +203,7 @@
 					 Test_cases[ind].exp_errno);
 			}
 		}
-		Tst_count++;	/* incr TEST_LOOP counter */
+		tst_count++;	/* incr TEST_LOOP counter */
 	}
 
 	/*