bpo-23855: Add missing NULL checks for malloc() in _msi.c (GH-9038)

(cherry picked from commit 4e519377b1b84c9414a360961276993d24198825)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>
diff --git a/PC/_msi.c b/PC/_msi.c
index d7700f0..68c4e79 100644
--- a/PC/_msi.c
+++ b/PC/_msi.c
@@ -321,6 +321,10 @@
     code = MsiRecordGetInteger(err, 1); /* XXX code */
     if (MsiFormatRecord(0, err, res, &size) == ERROR_MORE_DATA) {
         res = malloc(size+1);
+        if (res == NULL) {
+            MsiCloseHandle(err);
+            return PyErr_NoMemory();
+        }
         MsiFormatRecord(0, err, res, &size);
         res[size]='\0';
     }
@@ -544,6 +548,9 @@
         &fval, sval, &ssize);
     if (status == ERROR_MORE_DATA) {
         sval = malloc(ssize);
+        if (sval == NULL) {
+            return PyErr_NoMemory();
+        }
         status = MsiSummaryInfoGetProperty(si->h, field, &type, &ival,
             &fval, sval, &ssize);
     }