support/scripts/pkg-stats: don't buffer whole file searching for infra

The file handle can be iterated over directly and each line is used
exactly once, so the only effect of reading all lines into a list
first was higher memory use and complexity.

Signed-off-by: Fiona Klute <fiona.klute@gmx.de>
Signed-off-by: Arnout Vandecappelle <arnout@rnout.be>
(cherry picked from commit 07f7ad9898)
Signed-off-by: Thomas Perale <thomas.perale@mind.be>

support/scripts/pkg-stats

@@ -197,8 +197,7 @@ class Package:
 
         self.infras = list()
         with open(self.pkgfile, 'r') as f:
-            lines = f.readlines()
-            for line in lines:
+            for line in f:
                 match = INFRA_RE.match(line)
                 if not match:
                     continue