powerpc/mm: Fix typo in IS_ENABLED()

IS_ENABLED() matches names exactly, so the missing "CONFIG_" prefix
means this code would never be built.

Also fixes a missing newline in pr_warn().

Fixes: 970d54f9 ("powerpc/book3s64/hash: Disable 16M linear mapping size if not aligned")
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/202006050717.A2F9809E@keescook

arch/powerpc/mm/book3s64/hash_utils.c

@@ -663,11 +663,10 @@ static void __init htab_init_page_sizes(void)
 		 * Pick a size for the linear mapping. Currently, we only
 		 * support 16M, 1M and 4K which is the default
 		 */
-		if (IS_ENABLED(STRICT_KERNEL_RWX) &&
+		if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) &&
 		    (unsigned long)_stext % 0x1000000) {
 			if (mmu_psize_defs[MMU_PAGE_16M].shift)
-				pr_warn("Kernel not 16M aligned, "
-					"disabling 16M linear map alignment");
+				pr_warn("Kernel not 16M aligned, disabling 16M linear map alignment\n");
 			aligned = false;
 		}