Allow declarations after statements

We officially allow C99, so don't forbid this C99 feature.
diff --git a/programs/Makefile b/programs/Makefile
index 2cb7366..93bbb66 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -3,7 +3,7 @@
 # To compile with PKCS11: add "-lpkcs11-helper" to LDFLAGS
 
 CFLAGS	?= -O2
-WARNING_CFLAGS ?= -Wall -W -Wdeclaration-after-statement
+WARNING_CFLAGS ?= -Wall -W
 WARNING_CXXFLAGS ?= -Wall -W
 LDFLAGS ?=