Revert "libm: rename LIBC_PRIVATE to LIBC_DEPRECATED"

Vendor blobs strike back.

This reverts commit 9721bb3f0b7c8c45f42d2874c908a177615f42b5.

Bug: 
http://b/27518190

Change-Id: I3fbe71123840edc51a1a804f6c8e83c84958192d
diff --git a/libm/libm.arm.map b/libm/libm.arm.map
index 842f46c..e781f2d 100644
--- a/libm/libm.arm.map
+++ b/libm/libm.arm.map
@@ -272,7 +272,7 @@
     *;
 };
 
-LIBC_DEPRECATED { # arm mips
+LIBC_PRIVATE { # arm mips
   global: # arm mips
     ___Unwind_Backtrace; # arm
     ___Unwind_ForcedUnwind; # arm
diff --git a/libm/libm.map.txt b/libm/libm.map.txt
index d273603..075ebd5 100644
--- a/libm/libm.map.txt
+++ b/libm/libm.map.txt
@@ -271,7 +271,7 @@
     *;
 };
 
-LIBC_DEPRECATED { # arm mips
+LIBC_PRIVATE { # arm mips
   global: # arm mips
     ___Unwind_Backtrace; # arm
     ___Unwind_ForcedUnwind; # arm
diff --git a/libm/libm.mips.map b/libm/libm.mips.map
index 2429dba..476c6ad 100644
--- a/libm/libm.mips.map
+++ b/libm/libm.mips.map
@@ -272,7 +272,7 @@
     *;
 };
 
-LIBC_DEPRECATED { # arm mips
+LIBC_PRIVATE { # arm mips
   global: # arm mips
     __fixdfdi; # arm mips
     __fixsfdi; # arm mips