staging: sm750fb: use direct call to hw_sm750_output_setMode

The proc_setMode method in lynx_output always uses the same
implementation and there is no point to use redirection rather than
direct function call.

Signed-off-by: Mike Rapoport <mike.rapoport@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>