Revert DTB patches to in-place binary patches

Since we no longer need to add new properties in the device tree, and
all the patches we do removes strings, we can just directly patch
the flat device tree in-place, ignoring basically all the higher level
DTB structure and format to accomplish 100% compatibility.

native/jni/magiskboot/pattern.cpp

@@ -37,42 +37,27 @@ static int check_encryption_pattern(const char *s) {
 	else return -1;
 }
 
-char *patch_verity(const void *buf, uint32_t &size, bool inplace) {
-	auto src = static_cast<const char *>(buf);
-	auto dest = (char *)(inplace ? buf : xmalloc(size));
-	int src_size = size;
-	bool found = false;
+static uint32_t remove_pattern(void *buf, uint32_t size, int(*pattern_skip)(const char *)) {
+	auto src = static_cast<char *>(buf);
+	int orig_sz = size;
 	int write = 0;
-	for (int read = 0; read < src_size;) {
-		if (int skip; (skip = check_verity_pattern(src + read)) > 0) {
-			fprintf(stderr, "Found pattern [%.*s]\n", skip, src + read);
+	for (int read = 0; read < orig_sz;) {
+		if (int skip = pattern_skip(src + read); skip > 0) {
+			fprintf(stderr, "Remove pattern [%.*s]\n", skip, src + read);
 			size -= skip;
 			read += skip;
-			found = true;
 		} else {
-			dest[write++] = src[read++];
+			src[write++] = src[read++];
 		}
 	}
-	dest[write] = '\0';
-	if (!found) {
-		if (!inplace)
-			free(dest);
-		return nullptr;
-	}
-	return dest;
+	memset(src + write, 0, orig_sz - write);
+	return size;
 }
 
-void patch_encryption(void *buf, uint32_t &size) {
-	auto src = static_cast<char *>(buf);
-	int src_size = size;
-	int write = 0;
-	for (int read = 0; read < src_size; ++read, ++write) {
-		if (int skip; (skip = check_encryption_pattern(src + read)) > 0) {
-			fprintf(stderr, "Found pattern [%.*s]\n", skip, src + read);
-			size -= skip;
-			read += skip;
-		}
-		src[write] = src[read];
-	}
-	src[write] = '\0';
+uint32_t patch_verity(void *buf, uint32_t size) {
+	return remove_pattern(buf, size, check_verity_pattern);
+}
+
+uint32_t patch_encryption(void *buf, uint32_t size) {
+	return remove_pattern(buf, size, check_encryption_pattern);
 }