Correct cppcheck errors

ZFS buildbot STYLE builder was moved to Ubuntu 17.04
which has a newer version of cppcheck. Handle the
new cppcheck errors.

uu_* functions removed in this commit were unused
and effectively dead code. They are now retired.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Closes #6653

.github/suppressions.txt

@@ -0,0 +1,4 @@
+nullPointer:./module/zfs/zfs_vnops.c:839
+preprocessorErrorDirective:./module/zfs/vdev_raidz_math_avx512f.c:243
+preprocessorErrorDirective:./module/zfs/vdev_raidz_math_sse2.c:266
+

Makefile.am

@@ -69,8 +69,10 @@ lint: cppcheck paxcheck
 
 cppcheck:
 	@if type cppcheck > /dev/null 2>&1; then \
-		cppcheck --inline-suppr --quiet --force --error-exitcode=2 \
-		${top_srcdir}; \
+		cppcheck --quiet --force --error-exitcode=2 \
+			--suppressions-list=.github/suppressions.txt \
+			-UHAVE_SSE2 -UHAVE_AVX512F \
+			${top_srcdir}; \
 	fi
 
 paxcheck:

include/libuutil.h

@@ -98,12 +98,6 @@ extern int *uu_exit_ok(void);
 extern int *uu_exit_fatal(void);
 extern int *uu_exit_usage(void);
 
-/*
- * string->number conversions
- */
-extern int uu_strtoint(const char *, void *, size_t, int, int64_t, int64_t);
-extern int uu_strtouint(const char *, void *, size_t, int, uint64_t, uint64_t);
-
 /*
  * Debug print facility functions.
  */

lib/libuutil/Makefile.am

@@ -17,8 +17,7 @@ USER_C = \
 	uu_misc.c \
 	uu_open.c \
 	uu_pname.c \
-	uu_string.c \
-	uu_strtoint.c
+	uu_string.c
 
 KERNEL_C =
 

module/zfs/zfs_vnops.c

@@ -836,7 +836,6 @@ zfs_write(struct inode *ip, uio_t *uio, int ioflag, cred_t *cr)
 			    aiov->iov_base != abuf->b_data)) {
 				ASSERT(xuio);
 				dmu_write(zfsvfs->z_os, zp->z_id, woff,
-				    // cppcheck-suppress nullPointer
 				    aiov->iov_len, aiov->iov_base, tx);
 				dmu_return_arcbuf(abuf);
 				xuio_stat_wbuf_copied();