Avoid confusing "read prevented write" log messages.

Moving to a "function: message" style avoids ambiguity.

Change-Id: If9d590e50265c61725d3673bd03796e65edd2d5e
diff --git a/libc/bionic/__memset_chk.cpp b/libc/bionic/__memset_chk.cpp
index 72551f0..9a3be19 100644
--- a/libc/bionic/__memset_chk.cpp
+++ b/libc/bionic/__memset_chk.cpp
@@ -41,11 +41,11 @@
  * This memset check is called if _FORTIFY_SOURCE is defined and
  * greater than 0.
  */
-extern "C" void *__memset_chk (void *dest, int c, size_t n, size_t dest_len) {
-    if (__predict_false(n > dest_len)) {
-        __fortify_chk_fail("memset prevented write past end of buffer",
-                             BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW);
-    }
+extern "C" void* __memset_chk (void* dest, int c, size_t n, size_t dest_len) {
+  if (__predict_false(n > dest_len)) {
+    __fortify_chk_fail("memset: prevented write past end of buffer",
+                       BIONIC_EVENT_MEMSET_BUFFER_OVERFLOW);
+  }
 
-    return memset(dest, c, n);
+  return memset(dest, c, n);
 }