sv(4): fix free with zero size

[Jan Klemkow]

Hi,

The following diff fixes "free with zero size" in sv(4).  Builds and
stats the kernel with sv at pci and audio at sv enabled.

bye,
Jan

Index: dev/pci/sv.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/sv.c,v
retrieving revision 1.34
diff -u -p -r1.34 sv.c
--- dev/pci/sv.c        19 Sep 2016 06:46:44 -0000      1.34
+++ dev/pci/sv.c        13 May 2019 04:33:56 -0000
@@ -1286,7 +1286,7 @@ sv_malloc(void *addr, int direction, siz
                 return (0);
         error = sv_allocmem(sc, size, 16, p);
         if (error) {
-                free(p, pool, 0);
+                free(p, pool, sizeof(*p));
                return (0);
         }
         p->next = sc->sc_dmas;
@@ -1304,7 +1304,7 @@ sv_free(void *addr, void *ptr, int pool)
                 if (KERNADDR(*p) == ptr) {
                         sv_freemem(sc, *p);
                         *p = (*p)->next;
-                        free(*p, pool, 0);
+                        free(*p, pool, sizeof(**p));
                         return;
                 }
         }