e1000e: Release mutex lock only if it has been initially acquired

This patch fixes the issue of unlocking swflag_mutex for 82574 and 82583
devices regardless of if the hw semaphore has been successfully acquired via
e1000_get_hw_semaphore_82574(). With this patch, unlocking mutex now depends
on if the hw semaphore was successfully acquired before. And 82574/82583
devices are reset regardless of whether e1000_get_hw_semaphore_82574()
returns success or failure.

Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Akeem G Abodunrin <akeem.g.abodunrin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>