Remove extra line in warnings in ivfdec.c

The warnings give an extra line which is confusing sometimes.

This ports Jerome Jiang's libvpx commit 401c89653 to libaom:
https://chromium-review.googlesource.com/c/webm/libvpx/+/1054223

Change-Id: I11071a5a1ca362a7bc414a149c5279bdccaf9802

ivfdec.c

diff --git a/ivfdec.c b/ivfdec.c
index c2eb345..c3f7f0a 100644
--- a/ivfdec.c
+++ b/ivfdec.c
@@ -67,12 +67,12 @@
   size_t frame_size = 0;
 
   if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) != 1) {
-    if (!feof(infile)) warn("Failed to read frame size\n");
+    if (!feof(infile)) warn("Failed to read frame size");
   } else {
     frame_size = mem_get_le32(raw_header);
 
     if (frame_size > 256 * 1024 * 1024) {
-      warn("Read invalid frame size (%u)\n", (unsigned int)frame_size);
+      warn("Read invalid frame size (%u)", (unsigned int)frame_size);
       frame_size = 0;
     }
 
@@ -83,7 +83,7 @@
         *buffer = new_buffer;
         *buffer_size = 2 * frame_size;
       } else {
-        warn("Failed to allocate compressed data buffer\n");
+        warn("Failed to allocate compressed data buffer");
         frame_size = 0;
       }
     }
@@ -92,7 +92,7 @@
   if (!feof(infile)) {
     ASAN_UNPOISON_MEMORY_REGION(*buffer, *buffer_size);
     if (fread(*buffer, 1, frame_size, infile) != frame_size) {
-      warn("Failed to read full frame\n");
+      warn("Failed to read full frame");
       return 1;
     }