bnxt_en: fix error path of FW reset

When bnxt_open() fails in the firmware reset path, the driver needs to
gracefully abort, but it is executing code that should be invoked only
in the success path.  Define a function to abort FW reset and
consolidate all error paths to call this new function.

Fixes: dab62e7c ("bnxt_en: Implement faster recovery for firmware fatal error.")
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>