ubifs: Add logging functions for ubifs_msg, ubifs_err and ubifs_warn

ubifs: Add logging functions for ubifs_msg, ubifs_err and ubifs_warn

The existing logging macros are fairly large and converting the
macros to functions make the object code smaller.

Use %pV and __builtin_return_address(0) as appropriate.

$ size fs/ubifs/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 575831	 309688	 161312	1046831	  ff92f	fs/ubifs/built-in.o.allyesconfig.new
 622457	 312872	 161120	1096449	 10bb01	fs/ubifs/built-in.o.allyesconfig.old
 223785	    640	    644	 225069	  36f2d	fs/ubifs/built-in.o.defconfig.new
 251873	    640	    644	 253157	  3dce5	fs/ubifs/built-in.o.defconfig.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Richard Weinberger <richard@nod.at>