internal/rosa: use patch helper

This is significantly cleaner and runs somewhat faster.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/busybox.go

@@ -317,10 +317,6 @@ exec clang \
 EOF
 chmod +x /bin/gcc
 
-cd /usr/src/busybox
-chmod +w editors editors/awk.c
-patch -p 1 < /usr/src/patches/awk-fix-literal-backslash.patch
-
 cd "$(mktemp -d)"
 make \
 	KBUILD_SRC=/usr/src/busybox \
@@ -345,17 +341,16 @@ cp -v busybox /work/system/bin/
 ln -vs ../system/bin/hush /work/bin/sh
 mkdir -vp /work/usr/bin/
 ln -vs ../../system/bin/busybox /work/usr/bin/env
-`, pkg.Path(AbsUsrSrc.Append("busybox"), true, pkg.NewHTTPGetTar(
-		&http.Client{Transport: &http.Transport{
-			// busybox website is really slow to respond
-			TLSHandshakeTimeout: 2 * time.Minute,
-		}},
-		"https://busybox.net/downloads/busybox-"+version+".tar.bz2",
-		mustDecode(checksum),
-		pkg.TarBzip2,
-	)), pkg.Path(
-		AbsUsrSrc.Append("patches", "awk-fix-literal-backslash.patch"), false,
-		pkg.NewFile("awk-fix-literal-backslash.patch", []byte(`diff --git a/editors/awk.c b/editors/awk.c
+`, pkg.Path(AbsUsrSrc.Append("busybox"), true, t.NewPatchedSource(
+		"busybox", version, pkg.NewHTTPGetTar(
+			&http.Client{Transport: &http.Transport{
+				// busybox website is really slow to respond
+				TLSHandshakeTimeout: 2 * time.Minute,
+			}},
+			"https://busybox.net/downloads/busybox-"+version+".tar.bz2",
+			mustDecode(checksum),
+			pkg.TarBzip2,
+		), true, [2]string{"awk-fix-literal-backslash", `diff --git a/editors/awk.c b/editors/awk.c
 index 64e752f4b..40f5ba7f7 100644
 --- a/editors/awk.c
 +++ b/editors/awk.c
@@ -373,7 +368,7 @@ index 64e752f4b..40f5ba7f7 100644
 +				}
  				bslash = 0;
  			}
- 		}`)),
-	))
+ 		}`},
+	)))
 }
 func init() { artifactsF[Busybox] = Toolchain.newBusybox }