NFS breaks building kernel

Am I missing something obvious?  r193272 was committed on 20090601
(over 28 days ago), and I haven't seen anyone else report this
build failure.

hpc:root:exit:[220] cd /usr/src
hpc:root:exit:[221] svn update
hpc:root:exit:[222] make buildworld
(completes as expected)
hpc:root:exit:[223] make buildkernel
cc -c -O2 -frename-registers -pipe -fno-strict-aliasing -march=opteron
 -std=c99 -g -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes
  -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual  -Wundef
 -Wno-pointer-sign -fformat-extensions -nostdinc  -I. -I/usr/src/sys
 -I/usr/src/sys/contrib/altq -D_KERNEL -DHAVE_KERNEL_OPTION_HEADERS
 -include opt_global.h -fno-common -finline-limit=8000
 --param inline-unit-growth=100 --param large-function-growth=1000 
 -fno-omit-frame-pointer -mcmodel=kernel -mno-red-zone  -mfpmath=387
 -mno-sse -mno-sse2 -mno-sse3 -mno-mmx -mno-3dnow  -msoft-float
 -fno-asynchronous-unwind-tables -ffreestanding -fstack-protector
 -Werror  /usr/src/sys/nfsclient/nfs_socket.c
cc1: warnings being treated as errors
/usr/src/sys/nfsclient/nfs_socket.c: In function 'nfs_clnt_match_xid':
/usr/src/sys/nfsclient/nfs_socket.c:830: warning: 'return' with no value,
 in function returning non-void


hpc:root:exit:[224] svn blame /usr/src/sys/nfsclient/nfs_socket.c | head -840

193272        jhb static int
138496         ps nfs_clnt_match_xid(struct socket *so, 
138496         ps                  struct nfsmount *nmp, 
138496         ps                  struct mbuf *mrep)
138496         ps {
138496         ps       struct mbuf *md;
138496         ps       caddr_t dpos;
138496         ps       u_int32_t rxid, *tl;
138496         ps       struct nfsreq *rep;
138496         ps       int error;
138496         ps 
  1541    rgrimes       /*
  1541    rgrimes        * Search for any mbufs that are not a multiple of 4 bytes long
  1541    rgrimes        * or with m_data not longword aligned.
  1541    rgrimes        * These could cause pointer alignment problems, so copy them to
  1541    rgrimes        * well aligned mbufs.
  1541    rgrimes        */
138496         ps       if (nfs_realign(&mrep, 5 * NFSX_UNSIGNED) == ENOMEM) {
138496         ps               m_freem(mrep);
138496         ps               nfsstats.rpcinvalid++;
138496         ps               return;
138496         ps       }