reiserfs: correct misspelled "REISERFS_PROC_INFO" to "CONFIG_REISERFS_PROC_INFO"

Correct the misspelling of the preprocessor check of a Kconfig option to refer
to CONFIG_REISERFS_PROC_INFO and not just the incorrect REISERFS_PROC_INFO.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>