drm/qxl: Add space before open parentheses

Add space to remove checkpath.pl error:

ERROR: space required before the open parenthesis '('

Signed-off-by: Shayenne da Luz Moura <shayenneluzmoura@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1ab3ba05c140aae01bde66f73ff1f3b78bf7dfb3.1540579956.git.shayenneluzmoura@gmail.com


Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>