utils/check-package: cleanup line reading

Cleanup the implementation for reading lines by having files processed
in context managers and utilizing the iterable file object for line
reading (instead of needing to call `readlines()`).

Signed-off-by: James Knight <james.d.knight@live.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

utils/check-package

@@ -233,16 +233,18 @@ def check_file_using_lib(fname):
         nwarnings += warn
 
     lastline = ""
-    for lineno, text in enumerate(open(fname, "r", errors="surrogateescape").readlines()):
-        nlines += 1
-        for name, cf in objects:
-            if cf.disable.search(lastline):
-                continue
-            warn, fail = print_warnings(cf.check_line(lineno + 1, text), name in xfail)
-            if fail > 0:
-                failed.add(name)
-            nwarnings += warn
-        lastline = text
+    with open(fname, "r", errors="surrogateescape") as f:
+        for lineno, text in enumerate(f):
+            nlines += 1
+            for name, cf in objects:
+                if cf.disable.search(lastline):
+                    continue
+                line_sts = cf.check_line(lineno + 1, text)
+                warn, fail = print_warnings(line_sts, name in xfail)
+                if fail > 0:
+                    failed.add(name)
+                nwarnings += warn
+            lastline = text
 
     for name, cf in objects:
         warn, fail = print_warnings(cf.after(), name in xfail)