vgaarb: fix signal handling in vga_get()

vgaarb: fix signal handling in vga_get()

There are few defects in vga_get() related to signal hadning:

  - we shouldn't check for pending signals for TASK_UNINTERRUPTIBLE
    case;

  - if we found pending signal we must remove ourself from wait queue
    and change task state back to running;

  - -ERESTARTSYS is more appropriate, I guess.

Signed-off-by: Kirill A. Shutemov <[email protected]>
Cc: [email protected]
Reviewed-by: David Herrmann <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>