drm/i915/crt: Silence compiler warning for uninitialised status

drm/i915/crt: Silence compiler warning for uninitialised status

clang is confused by our if-else-chain that abruptly exits before a
final else:

drivers/gpu/drm/i915/intel_crt.c:821:11: warning: variable 'status' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
        else if (ret < 0)
                 ^~~~~~~
drivers/gpu/drm/i915/intel_crt.c:826:9: note: uninitialized use occurs here
        return status;
               ^~~~~~
drivers/gpu/drm/i915/intel_crt.c:821:7: note: remove the 'if' if its condition is always true
        else if (ret < 0)
             ^~~~~~~~~~~~
drivers/gpu/drm/i915/intel_crt.c:761:12: note: initialize the variable 'status' to silence this warning
        int status, ret;

In this case, we can reduce the final else-if clause to an unconditional
else.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180208163939.27030-1-chris@chris-wilson.co.uk