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/creat/creat01.c b/testcases/kernel/syscalls/creat/creat01.c
index fd90d0c..5cb3823 100644
--- a/testcases/kernel/syscalls/creat/creat01.c
+++ b/testcases/kernel/syscalls/creat/creat01.c
@@ -98,7 +98,7 @@
 
 	for (lc = 0; TEST_LOOPING(lc); lc++) {
 
-		Tst_count = 0;
+		tst_count = 0;
 
 		for (i = 0; i < TST_TOTAL; i++) {
 			TEST(fd = creat(filename, TC[i].mode));