NFSD: Use "depends on" for PROC_FS dependency

Recently, commit 440bcc59 added a reverse dependency to fs/Kconfig to
ensure that PROC_FS was enabled if NFSD_V4 was enabled.

There is a guideline in Documentation/kbuild/kconfig-language.txt that
states "In general use select only for non-visible symbols (no prompts
anywhere) and for symbols with no dependencies."

A quick grep around other Kconfig files reveals that no entry currently
uses "select PROC_FS" -- every one uses "depends on".  Thus CONFIG_NFSD_V4
should use "depends on PROC_FS" as well.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/Kconfig

@@ -1695,7 +1695,6 @@ config NFSD
 	select SUNRPC
 	select EXPORTFS
 	select NFS_ACL_SUPPORT if NFSD_V2_ACL
-	select PROC_FS if NFSD_V4
 	select PROC_FS if SUNRPC_GSS
 	help
 	  Choose Y here if you want to allow other computers to access
@@ -1757,7 +1756,7 @@ config NFSD_V3_ACL
 
 config NFSD_V4
 	bool "NFS server support for NFS version 4 (EXPERIMENTAL)"
-	depends on NFSD && NFSD_V3 && EXPERIMENTAL
+	depends on NFSD && NFSD_V3 && PROC_FS && EXPERIMENTAL
 	select FS_POSIX_ACL
 	select RPCSEC_GSS_KRB5
 	help