utils: Convert pollfd array to be allocated

Convert the struct pollfd *fds to be allocated rather than residing
on the stack. This prepares it for the next patch where the size of
the array of fds becomes dynamic.
Signed-off-by: NStefan Berger <stefanb@linux.ibm.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

src/util/vircommand.c

@@ -2142,6 +2142,7 @@ virCommandProcessIO(virCommandPtr cmd)
     size_t inlen = 0, outlen = 0, errlen = 0;
     size_t inoff = 0;
     int ret = 0;
+    VIR_AUTOFREE(struct pollfd *) fds = NULL;
 
     if (dryRunBuffer || dryRunCallback) {
         VIR_DEBUG("Dry run requested, skipping I/O processing");
@@ -2173,9 +2174,11 @@ virCommandProcessIO(virCommandPtr cmd)
         goto cleanup;
     ret = -1;
 
+    if (VIR_ALLOC_N(fds, 3) < 0)
+        goto cleanup;
+
     for (;;) {
         size_t i;
-        struct pollfd fds[3];
         int nfds = 0;
 
         if (cmd->inpipe != -1) {