V4L/DVB (13038): dvbdev: Remove an anoying/uneeded warning

As pointed by Marcin Slusarz <marcin.slusarz@gmail.com>, the warns happens
because CONFIG_DVB_MAX_ADAPTERS depends on CONFIG_DVB_CORE, and there are
valid configs where DVB_CORE is not selected.

This causes such warnings, for every V4L and common drivers that may or
may not be compiled with DVB support:

drivers/media/dvb/dvb-core/dvbdev.h:36:2: warning: #warning invalid CONFIG_DVB_MAX_ADAPTERS value

We can safely remove the warning.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/dvb-core/dvbdev.h

@@ -31,10 +31,9 @@
 #define DVB_MAJOR 212
 
 #if defined(CONFIG_DVB_MAX_ADAPTERS) && CONFIG_DVB_MAX_ADAPTERS > 0
-#define DVB_MAX_ADAPTERS CONFIG_DVB_MAX_ADAPTERS
+  #define DVB_MAX_ADAPTERS CONFIG_DVB_MAX_ADAPTERS
 #else
-#warning invalid CONFIG_DVB_MAX_ADAPTERS value
-#define DVB_MAX_ADAPTERS 8
+  #define DVB_MAX_ADAPTERS 8
 #endif
 
 #define DVB_UNSET (-1)