vfs_syscalls changes break building NET4501 i386 kernel

["John D. Baker" <jdbaker%mylinuxisp.com@localhost>]

Following this commit:

  http://mail-index.netbsd.org/source-changes/2015/10/23/msg069628.html

Building NET4501 kernel fails with:

--- vfs_syscalls.o ---
#   compile  NET4501/vfs_syscalls.o
/d0/build/nbsd-tst/tools/amd64/bin/i486--netbsdelf-gcc -msoft-float -mno-mmx -mno-sse -mno-avx -ffreestanding -fno-zero-initialized-in-bss -Os -fstack-protector -Wstack-protector --param ssp-buffer-size=1 -fno-strict-aliasing -fno-common -std=gnu99 -Werror -Wall -Wno-main -Wno-format-zero-length -Wpointer-arith -Wmissing-prototypes -Wstrict-prototypes -Wold-style-definition -Wswitch -Wshadow -Wcast-qual -Wwrite-strings -Wno-unreachable-code -Wno-pointer-sign -Wno-attributes -Wextra -Wno-unused-parameter -Wold-style-definition -Wno-sign-compare --sysroot=/d0/build/nbsd-tst/DEST/i386 -Di386 -I. -I/x/nbsd-tst/src/sys/external/bsd/acpica/dist -I/x/nbsd-tst/src/sys/../common/lib/libx86emu -I/x/nbsd-tst/src/sys/../common/include -I/x/nbsd-tst/src/sys/arch -I/x/nbsd-tst/src/sys -nostdinc -DTIMER_FREQ=1189200 -D_KERNEL -D_KERNEL_OPT -std=gnu99 -I/x/nbsd-tst/src/sys/lib/libkern/../../../common/lib/libc/quad -I/x/nbsd-tst/src/sys/lib/libkern/../../../common/lib/libc/string -I/x/nbsd-tst/src/sys/lib/libkern/../../../common/lib/libc/arch/i386/string -D_FORTIFY_SOURCE=2 -I/x/nbsd-tst/src/sys/external/bsd/ipf -I/x/nbsd-tst/src/sys/external/isc/atheros_hal/dist -I/x/nbsd-tst/src/sys/external/isc/atheros_hal/ic -c /x/nbsd-tst/src/sys/kern/vfs_syscalls.c -o vfs_syscalls.o
/x/nbsd-tst/src/sys/kern/vfs_syscalls.c: In function 'do_sys_mount':
/x/nbsd-tst/src/sys/kern/vfs_syscalls.c:544:13: error: 'vfsops' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   vfs_delref(vfsops);
             ^
cc1: all warnings being treated as errors
*** [vfs_syscalls.o] Error code 1

nbmake: stopped in /d0/build/nbsd-tst/obj/i386/sys/arch/i386/compile/NET4501
1 error

nbmake: stopped in /d0/build/nbsd-tst/obj/i386/sys/arch/i386/compile/NET4501

ERROR: Failed to make all in "/d0/build/nbsd-tst/obj/i386/sys/arch/i386/compile/NET4501"
*** BUILD ABORTED ***

-- 
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