For libm, use a macro for aliasing symbols.

Change-Id: Ibd42ebc387c2bf3eba9aa96091770915b4b34184
diff --git a/libm/x86/e_log.S b/libm/x86/e_log.S
index b5df1ea..a6181ca 100644
--- a/libm/x86/e_log.S
+++ b/libm/x86/e_log.S
@@ -231,8 +231,7 @@
 # -- End  log
 
 # Start file scope ASM
-.weak logl
-.equ logl, log
+ALIAS_SYMBOL(logl, log);
 # End file scope ASM
 	.section .rodata, "a"
 	.align 16