ice: Fix signedness bug in ice_init_interrupt_scheme()

ice: Fix signedness bug in ice_init_interrupt_scheme()

If pci_alloc_irq_vectors() can't allocate the minimum number of vectors
then it returns -ENOSPC so there is no need to check for that in the
caller.  In fact, because pf->msix.min is an unsigned int, it means that
any negative error codes are type promoted to high positive values and
treated as success.  So here, the "return -ENOMEM;" is unreachable code.
Check for negatives instead.

Now that we're only dealing with error codes, it's easier to propagate
the error code from pci_alloc_irq_vectors() instead of hardcoding
-ENOMEM.

Fixes: 79d97b8cf9a8 ("ice: remove splitting MSI-X between features")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://patch.msgid.link/b16e4f01-4c85-46e2-b602-fce529293559@stanley.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>