ctlstat not building with clang

Building world with clang now (as of r229997) no longer compiles because
ctlstat was imported into the tree.  The error is:

clang -O2 -pipe  -I/usr/src/usr.bin/ctlstat/../../sys -std=gnu99
-fstack-protector -Wsystem-headers -Werror -Wall -Wno-format-y2k -W
-Wno-unused-parameter -Wstrict-prototypes -Wmissing-prototypes
-Wpointer-arith -Wreturn-type -Wcast-qual -Wwrite-strings -Wswitch -Wshadow
-Wunused-parameter -Wcast-align -Wchar-subscripts -Winline -Wnested-externs
-Wredundant-decls -Wold-style-definition -Wno-pointer-sign -c
/usr/src/usr.bin/ctlstat/ctlstat.c
/usr/src/usr.bin/ctlstat/ctlstat.c:149:35: error: format string is not a
string literal (potentially insecure)
      [-Werror,-Wformat-security]
        fprintf(error ? stderr : stdout, ctlstat_usage);
                                         ^~~~~~~~~~~~~
1 error generated.
*** Error code 1

Stop in /usr/src/usr.bin/ctlstat

How do people feel about the attached patch that turns a call to fprintf to
fputs?