fm10k: explicitly return 0 on success path in function

fm10k: explicitly return 0 on success path in function

In the fm10k_handle_resume function, return 0 explicitly at the end of
the function instead of returning the err value.

This was detected by cppcheck and resolves the following style warning
produced by that tool:

[fm10k_pci.c:2768] -> [fm10k_pci.c:2787]: (warning) Identical condition
'err', second condition is always false

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>