genheaders: %-<width>s had been there since v6; %-*s - since v7

genheaders: %-<width>s had been there since v6; %-*s - since v7

Please, use at least K&R C; printf had been able to left-adjust
a field for as long as stdio existed and use of '*' for variable
width had been there since v7.  Yes, the first edition of K&R
didn't cover the latter feature (it slightly predates v7), but
you are using a much later feature of the language than that -
in K&R C
static char *stoupperx(const char *s)
{
...
}
would've been spelled as
static char *stoupperx(s)
char *s;
{
...
}

While we are at it, the use of strstr() is bogus - it finds the
_first_ instance of substring, so it's a lousy fit for checking
if a string ends with given suffix...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>