bnx2x: fix resource allocattion error handling

bnx2x: fix resource allocattion error handling

bnx2x_loop_obtain_resources() returns a struct containing the status and
the error message.  If bnx2x_do_req4pf() fails, it shouldn't return both
of these fields set to 0 indicating failure and no error.

Further, bnx2x_do_req4pf() needs to be able fail and return NO_RESOURCES
so that bnx2x_loop_obtain_resources() can negotiate reduced resource
requirments.  This requires additional checking around bnx2x_do_req4pf().

Fixes: 540a211084a7 ("bnx2x: driver core")

Signed-off-by: Chas Williams <3chas3@gmail.com>
Acked-by: Rasesh Mody <rasesh.mody@qlogic.com>