mm: fix typo in struct vm_operations_struct comments

There is no eprotect(), so I assume this is about mprotect().

Link: https://lkml.kernel.org/r/2385684.8vm7BOzihM@mobilepool36.emlix.com


Signed-off-by: Rolf Eike Beer <eb@emlix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>