liblog: remove LIBLOG_WEAK

I'm not sure why I didn't remove this when I got rid of the other
functions marked as weak.

Test: build
Change-Id: I45e6bca7be0497e33be88d15afea8bb1d5165380
diff --git a/liblog/logprint.cpp b/liblog/logprint.cpp
index bc056cb..cec5d96 100644
--- a/liblog/logprint.cpp
+++ b/liblog/logprint.cpp
@@ -1145,7 +1145,7 @@
  * _also_ be part of libutils/Unicode.cpp if its usefullness needs to
  * propagate globally.
  */
-LIBLOG_WEAK ssize_t utf8_character_length(const char* src, size_t len) {
+static ssize_t utf8_character_length(const char* src, size_t len) {
   const char* cur = src;
   const char first_char = *cur++;
   static const uint32_t kUnicodeMaxCodepoint = 0x0010FFFF;