dtc: Add -Wredundant-decls (resend)

We are almost clean already with the -Wredundant-decls warning.  The
only exception is a declaration for isatty() inside the flex-generated
code.  This can be removed by using flex's "never-interactive" option,
which we probably should be using anyway, since we never parse
interactively in the sense that this option implies.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Makefile

@@ -17,7 +17,7 @@ CONFIG_LOCALVERSION =
 
 CPPFLAGS = -I libfdt
 WARNINGS = -Werror -Wall -Wpointer-arith -Wcast-qual -Wnested-externs \
-	-Wstrict-prototypes -Wmissing-prototypes
+	-Wstrict-prototypes -Wmissing-prototypes -Wredundant-decls
 CFLAGS = -g -Os -fPIC -Werror $(WARNINGS)
 
 BISON = bison

convert-dtsv0-lexer.l

@@ -17,7 +17,7 @@
  *                                                                   USA
  */
 
-%option noyywrap nounput noinput
+%option noyywrap nounput noinput never-interactive
 
 %x INCLUDE
 %x BYTESTRING

dtc-lexer.l

@@ -18,7 +18,7 @@
  *                                                                   USA
  */
 
-%option noyywrap nounput noinput
+%option noyywrap nounput noinput never-interactive
 
 %x INCLUDE
 %x BYTESTRING