util/printf: Expose util_printf_prev_tok

Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25753>

src/util/u_printf.c

@@ -38,7 +38,7 @@
 _CRTIMP int _vscprintf(const char *format, va_list argptr);
 #endif
 
-static const char*
+const char*
 util_printf_prev_tok(const char *str)
 {
    while (*str != '%')

src/util/u_printf.h

@@ -37,6 +37,8 @@ typedef struct u_printf_info {
    char *strings;
 } u_printf_info;
 
+const char *util_printf_prev_tok(const char *str);
+
 /* find next valid printf specifier in a C string wrapper */
 size_t util_printf_next_spec_pos(const char *str, size_t pos);