EDAC: Fix mem_types strings type

This one got forgotten during an earlier cleanup.

Signed-off-by: Borislav Petkov <bp@suse.de>
diff --git a/drivers/edac/edac_core.h b/drivers/edac/edac_core.h
index 3c2625e..6c9f381 100644
--- a/drivers/edac/edac_core.h
+++ b/drivers/edac/edac_core.h
@@ -66,7 +66,7 @@
 #define EDAC_PCI "PCI"
 #define EDAC_DEBUG "DEBUG"
 
-extern const char *edac_mem_types[];
+extern const char * const edac_mem_types[];
 
 #ifdef CONFIG_EDAC_DEBUG
 extern int edac_debug_level;