PCI: xgene: Remove unused assignment to variable msi_val

PCI: xgene: Remove unused assignment to variable msi_val

The value assigned to msi_val after the inner loop finishes its run is
never used for anything, and it is also immediately overridden in the
line that follows with the return value from the xgene_msi_int_read()
function.

Since the value of msi_val following the inner loop completion is never
used in any meaningful way the assignment can be removed.

Addresses-Coverity-ID: 1437183 ("Unused value")
Link: https://lore.kernel.org/r/20200922030257.459898-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>