libm: disable tail jump trick if __SSP_ALL__ (was using wrong conditional)

Thanks, Timo!

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

docs/defines.txt

@@ -79,3 +79,7 @@ _IEEE_LIBM
     Always defined at libm build time
 __LDBL_COMPAT
     Never defined, TODO: remove?
+
+__SSP_ALL__
+    All functions, even small ones, have stack smashing protection
+    prologue enabled.

libm/ldouble_wrappers.c

@@ -37,7 +37,7 @@ long long func##l(long double x) \
 	return func((double) x); \
 }
 
-#if defined __i386__ && defined __OPTIMIZE__ && !defined __UCLIBC_HAS_SSP__
+#if defined __i386__ && defined __OPTIMIZE__ && !defined __SSP_ALL__
 # undef WRAPPER1
 # undef int_WRAPPER1
 # undef long_WRAPPER1