generate-sys-test: modernize Python and C code

Meson itself requires Python 3.6, which has f-strings. So I think it's fine to
use them here too. I wanted to use walrus for 'if m:= re.search(...)', but that'd
require 3.8.

diff --git a/src/test/generate-sym-test.py b/src/test/generate-sym-test.py
index fdb9e3ecb789600f66ed77c10ddb08058e53010b..b391646af64f5604297df9f805691f98774a9244 100755 (executable)
--- a/src/test/generate-sym-test.py
+++ b/src/test/generate-sym-test.py
@@ -16,15 +16,14 @@ for line in open(sys.argv[1]):
     if match:
         s = match.group(1)
         if s == 'sd_bus_object_vtable_format':
-            print('    &{},'.format(s))
+            print(f'    &{s},')
         else:
-            print('    {},'.format(s))
+            print(f'    {s},')
 
 print('''};
 
 int main(void) {
-    unsigned i;
-    for (i = 0; i < sizeof(symbols)/sizeof(void*); i++)
+    for (size_t i = 0; i < sizeof(symbols)/sizeof(void*); i++)
          printf("%p\\n", symbols[i]);
     return 0;
 }''')