NULL checks should be before the first dereference.

Spotted by the Coverity checker.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NOndrej Zajicek <santiago@crfreenet.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Toralf Förster pointed out that drivers/video/s3fb.c would fail to compile:
> ...
>   CC      drivers/video/s3fb.o
> drivers/video/s3fb.c: In function `s3_pci_remove':
> drivers/video/s3fb.c:1003: warning: unused variable `par'
> drivers/video/s3fb.c: In function `s3fb_setup':
> drivers/video/s3fb.c:1141: error: `mtrr' undeclared (first use in this function)
> drivers/video/s3fb.c:1141: error: (Each undeclared identifier is reported only once
> drivers/video/s3fb.c:1141: error: for each function it appears in.)
> make[2]: *** [drivers/video/s3fb.o] Error 1
> make[1]: *** [drivers/video] Error 2
> make: *** [drivers] Error 2

Here is fix, it also fixes broken boot options.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a driver for S3 Trio / S3 Virge.  Driver is tested with most versions
of S3 Trio and with S3 Virge/DX, on i386.

(akpm: We kind-of have support for this hardware already, but...

virgefb.c
  - amiga/zorro specific,
  - broken (according to Kconfig),
  - uses obsolete/nonexistent interface (struct display_switch)
  - recent Adrian Bunk's patch removes this driver

S3triofb.c
  - ppc/openfirmware specific
  - minimal functionality
  - broken (according to Kconfig),
  - uses obsolete/nonexistent interface (struct display_switch)
)
Signed-off-by: NOndrej Zajicek <santiago@crfreenet.org>
Cc: James Simmons <jsimmons@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>