fs/eventpoll.c: simply CONFIG_NET_RX_BUSY_POLL ifdefery

... 'tis easier on the eye.

[akpm@linux-foundation.org: use inlines rather than macros]
Link: http://lkml.kernel.org/r/20180725185620.11020-1-dave@stgolabs.net


Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>