Fix uninitialized variable in zstream redup command

The 'rdt.ddt_count' variable is uninitialized because it was
allocated from the stack and not globally.  Initialize it.
This was reported by gcc when compiling with debugging enabled.

    zstream_redup.c:157:16: error: 'rdt.ddt_count' may be used
    uninitialized in this function [-Werror=maybe-uninitialized]

Signed-off-by: Brian Behlendorf <[email protected]>

cmd/zstream/zstream_redup.c

@@ -218,6 +218,7 @@ zfs_redup_stream(int infd, int outfd, boolean_t verbose)
 	rdt.ddecache = umem_cache_create("rde", sizeof (redup_entry_t), 0,
 	    NULL, NULL, NULL, NULL, NULL, 0);
 	rdt.numhashbits = highbit64(numbuckets) - 1;
+	rdt.ddt_count = 0;
 
 	char *buf = safe_calloc(bufsz);
 	FILE *ofp = fdopen(infd, "r");