mmc: Standardize header file inclusion checks.

Standardize the checks for multiple MMC header file inclusion,
including adding comments to terminating #endif's, and fixing
one incorrect comment.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index bdd7cee..55d9909 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -11,8 +11,8 @@
  * (at your option) any later version.
  */
 
-#ifndef _LINUX_MMC_DW_MMC_H_
-#define _LINUX_MMC_DW_MMC_H_
+#ifndef LINUX_MMC_DW_MMC_H
+#define LINUX_MMC_DW_MMC_H
 
 #define MAX_MCI_SLOTS	2
 
@@ -219,4 +219,4 @@
 	struct block_settings *blk_settings;
 };
 
-#endif /* _LINUX_MMC_DW_MMC_H_ */
+#endif /* LINUX_MMC_DW_MMC_H */