global: remove unnecessary horizontal tabs.

This change was made by applying emacs' untabify function to
nearly all files in Bison's repository.  Required tabs in make
files, ChangeLog, regexps, and test code were manually skipped.
Other notable exceptions and changes are listed below.
* bootstrap: Skip because we sync this with gnulib.
* data/m4sugar/foreach.m4
* data/m4sugar/m4sugar.m4: Skip because we sync these with
Autoconf.
* djgpp: Skip because I don't know how to test djgpp properly, and
this code appears to be unmaintained anyway.
* README-hacking (Hacking): Specify that tabs should be avoided
where not required.

src/complain.c

@@ -47,8 +47,8 @@ static unsigned *indent_ptr = 0;
 static
 void
 error_message (location *loc,
-	       const char *prefix,
-	       const char *message, va_list args)
+               const char *prefix,
+               const char *message, va_list args)
 {
   unsigned pos = 0;
 
@@ -81,12 +81,12 @@ error_message (location *loc,
 }
 
 /** Wrap error_message() with varargs handling. */
-#define ERROR_MESSAGE(Loc, Prefix, Message)	\
-{						\
-  va_list args;					\
-  va_start (args, Message);			\
-  error_message (Loc, Prefix, Message, args);	\
-  va_end (args);				\
+#define ERROR_MESSAGE(Loc, Prefix, Message)     \
+{                                               \
+  va_list args;                                 \
+  va_start (args, Message);                     \
+  error_message (Loc, Prefix, Message, args);   \
+  va_end (args);                                \
 }