[media] s5p_mfc: don't use an external symbol called 'debug'

The 'debug' name is known to cause conflicts with allyesconfig
on several archs. So, localize its name.

>> drivers/built-in.o:(.bss+0xc7ee2c): multiple definition of `debug'
   arch/x86/built-in.o:(.entry.text+0xf78): first defined here
   ld: Warning: size of symbol `debug' changed from 86 in arch/x86/built-in.o to 4 in drivers/built-in.o

While here, fix a wrong file name reference

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c
index d35b041..89b5b4a 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -37,8 +37,8 @@
 #define S5P_MFC_DEC_NAME	"s5p-mfc-dec"
 #define S5P_MFC_ENC_NAME	"s5p-mfc-enc"
 
-int debug;
-module_param(debug, int, S_IRUGO | S_IWUSR);
+int mfc_debug_level;
+module_param_named(debug, mfc_debug_level, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(debug, "Debug level - higher value produces more verbose messages");
 
 /* Helper functions for interrupt processing */