Apply the semantic patch rm-malloc-cast.cocci.

    for dir in library programs; do
        spatch --sp-file scripts/rm-malloc-cast.cocci --dir $dir \
        --in-place;
    done
diff --git a/library/pem.c b/library/pem.c
index aeaa4b6..b71e666 100644
--- a/library/pem.c
+++ b/library/pem.c
@@ -319,7 +319,7 @@
     if( ret == POLARSSL_ERR_BASE64_INVALID_CHARACTER )
         return( POLARSSL_ERR_PEM_INVALID_DATA + ret );
 
-    if( ( buf = (unsigned char *) polarssl_malloc( len ) ) == NULL )
+    if( ( buf = polarssl_malloc( len ) ) == NULL )
         return( POLARSSL_ERR_PEM_MALLOC_FAILED );
 
     if( ( ret = base64_decode( buf, &len, s1, s2 - s1 ) ) != 0 )