EINVAL means that the filesystem doesn't support posix_fallocate().

There were two places where this error was issued, one checked for
EINVAL, the other did not. This commit fixed the other place
to also check for EINVAL.

Also, remove the space after the REFMAN to get the valid url
with no space in the middle.

Also don't say "Make sure the file system supports this function."
when posix_fallocate() fails, because this message is only shown
when the filesystem does support this function.