dissect: pick up gpt partition flags

Let's store the GPT partition flags in the dissected partition info.

Right now we won't actually use them for anything yet, but later we'll
add that, when enforcing policy on dissection.

src/shared/dissect-image.c

@@ -934,6 +934,7 @@ static int dissect_image(
                                         .mount_node_fd = TAKE_FD(mount_node_fd),
                                         .offset = (uint64_t) start * 512,
                                         .size = (uint64_t) size * 512,
+                                        .gpt_flags = pflags,
                                 };
                         }
 

src/shared/dissect-image.h

@@ -33,6 +33,7 @@ struct DissectedPartition {
         int mount_node_fd;
         uint64_t size;
         uint64_t offset;
+        uint64_t gpt_flags;
 };
 
 #define DISSECTED_PARTITION_NULL                                        \