Avoid confusing "read prevented write" log messages.

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

Change-Id: If9d590e50265c61725d3673bd03796e65edd2d5e
diff --git a/libc/bionic/__vsnprintf_chk.cpp b/libc/bionic/__vsnprintf_chk.cpp
index a03d12f..ecf5816 100644
--- a/libc/bionic/__vsnprintf_chk.cpp
+++ b/libc/bionic/__vsnprintf_chk.cpp
@@ -42,19 +42,13 @@
  * This vsnprintf check is called if _FORTIFY_SOURCE is defined and
  * greater than 0.
  */
-extern "C" int __vsnprintf_chk(
-        char *dest,
-        size_t supplied_size,
-        int /*flags*/,
-        size_t dest_len_from_compiler,
-        const char *format,
-        va_list va)
-{
-    if (__predict_false(supplied_size > dest_len_from_compiler)) {
-        __fortify_chk_fail("vsnprintf prevented write past end of buffer", 0);
-    }
+extern "C" int __vsnprintf_chk(char* dest, size_t supplied_size, int /*flags*/,
+                               size_t dest_len_from_compiler, const char* format, va_list va) {
+  if (__predict_false(supplied_size > dest_len_from_compiler)) {
+    __fortify_chk_fail("vsnprintf: prevented write past end of buffer", 0);
+  }
 
-    return vsnprintf(dest, supplied_size, format, va);
+  return vsnprintf(dest, supplied_size, format, va);
 }
 
 /*
@@ -68,20 +62,11 @@
  * This snprintf check is called if _FORTIFY_SOURCE is defined and
  * greater than 0.
  */
-extern "C" int __snprintf_chk(
-        char *dest,
-        size_t supplied_size,
-        int flags,
-        size_t dest_len_from_compiler,
-        const char *format, ...)
-{
-    va_list va;
-    int retval;
-
-    va_start(va, format);
-    retval = __vsnprintf_chk(dest, supplied_size, flags,
-                             dest_len_from_compiler, format, va);
-    va_end(va);
-
-    return retval;
+extern "C" int __snprintf_chk(char* dest, size_t supplied_size, int flags,
+        size_t dest_len_from_compiler, const char* format, ...) {
+  va_list va;
+  va_start(va, format);
+  int result = __vsnprintf_chk(dest, supplied_size, flags, dest_len_from_compiler, format, va);
+  va_end(va);
+  return result;
 }