eal/x86: drop export of internal alignment macro

[ upstream commit 11f61ea2f6fcdd88df2a81b82235ddb7033c3e5d ]

ALIGNMENT_MASK is only used internally.
Besides it lacks a DPDK-related prefix.
Hide it from external eyes.

Fixes: f547270 ("eal: optimize aligned memcpy on x86")

Reported-by: Morten Brørup <mb@smartsharesystems.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>

lib/librte_eal/common/include/arch/x86/rte_memcpy.h

@@ -851,6 +851,8 @@ rte_memcpy(void *dst, const void *src, size_t n)
 		return rte_memcpy_generic(dst, src, n);
 }
 
+#undef ALIGNMENT_MASK
+
 #if defined(RTE_TOOLCHAIN_GCC) && (GCC_VERSION >= 100000)
 #pragma GCC diagnostic pop
 #endif