lib/flex_proportions.c: remove local_irq_ops in fprop_new_period()

lib/flex_proportions.c: remove local_irq_ops in fprop_new_period()

commit e78d4833c03e28> "lib: Fix possible deadlock in flexible proportion
code" adds the local_irq_ops because percpu_counter_{sum |add} ops'lock
can cause deadlock by interrupts.  Now percpu_counter _{sum|add} ops use
raw_spin_(un)lock_irq*, so revert the commit and resolve the conflict.

Link: https://lkml.kernel.org/r/20220604131502.5190-1-wuchi.zero@gmail.com
Signed-off-by: wuchi <wuchi.zero@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>