avfilter/tests/integral: Check malloc fail before using it

Need to check malloc fail before using it, so adjust the location
in the code.
Reviewed-by: NMichael Niedermayer <michaelni@gmx.at>
Signed-off-by: NJun Zhao <mypopydev@gmail.com>

libavfilter/tests/integral.c

@@ -54,6 +54,9 @@ int main(void)
     uint32_t *ii  = av_mallocz_array(ii_h + 1, ii_lz_32 * sizeof(*ii));
     uint32_t *ii2 = av_mallocz_array(ii_h + 1, ii_lz_32 * sizeof(*ii2));
 
+    if (!ii || !ii2)
+        return -1;
+
     uint32_t *ii_start  = ii  + ii_lz_32 + 1; // skip top 0-line and left 0-column
     uint32_t *ii_start2 = ii2 + ii_lz_32 + 1; // skip top 0-line and left 0-column
 
@@ -61,9 +64,6 @@ int main(void)
 
     ff_nlmeans_init(&dsp);
 
-    if (!ii || !ii2)
-        return -1;
-
     for (yoff = -e; yoff <= e; yoff++) {
         for (xoff = -e; xoff <= e; xoff++) {
             printf("xoff=%d yoff=%d\n", xoff, yoff);