drm/vmwgfx: Use preprocessor macro for FIFO allocation

Whenever FIFO allocation fails an error message is printed to dmesg.
Since this is common operation a lot of similar messages are scattered
everywhere. Use preprocessor macro to remove this cluttering.

Signed-off-by: Deepak Rawat <drawat@vmware.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>