Use ctx.Fatalln instead of log.Fatalln for absolute path errors

log.Fatalln calls os.Exit, which skips deferred functions and
leaves the console with the cursor disabled.  Use ctx.Fatalln
instead, which uses a panic to exit and calls the deferred
function to restore the cursor.

Test: DIST_DIR=/tmp/\test\ foo m dist
Change-Id: Ie92297075e37c171d5ba48848a0ddb19652b051c
diff --git a/ui/build/config.go b/ui/build/config.go
index 665d2f0..def3345 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -16,7 +16,6 @@
 
 import (
 	"io/ioutil"
-	"log"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -189,27 +188,27 @@
 	checkTopDir(ctx)
 
 	if srcDir := absPath(ctx, "."); strings.ContainsRune(srcDir, ' ') {
-		log.Println("You are building in a directory whose absolute path contains a space character:")
-		log.Println()
-		log.Printf("%q\n", srcDir)
-		log.Println()
-		log.Fatalln("Directory names containing spaces are not supported")
+		ctx.Println("You are building in a directory whose absolute path contains a space character:")
+		ctx.Println()
+		ctx.Printf("%q\n", srcDir)
+		ctx.Println()
+		ctx.Fatalln("Directory names containing spaces are not supported")
 	}
 
 	if outDir := ret.OutDir(); strings.ContainsRune(outDir, ' ') {
-		log.Println("The absolute path of your output directory ($OUT_DIR) contains a space character:")
-		log.Println()
-		log.Printf("%q\n", outDir)
-		log.Println()
-		log.Fatalln("Directory names containing spaces are not supported")
+		ctx.Println("The absolute path of your output directory ($OUT_DIR) contains a space character:")
+		ctx.Println()
+		ctx.Printf("%q\n", outDir)
+		ctx.Println()
+		ctx.Fatalln("Directory names containing spaces are not supported")
 	}
 
 	if distDir := ret.DistDir(); strings.ContainsRune(distDir, ' ') {
-		log.Println("The absolute path of your dist directory ($DIST_DIR) contains a space character:")
-		log.Println()
-		log.Printf("%q\n", distDir)
-		log.Println()
-		log.Fatalln("Directory names containing spaces are not supported")
+		ctx.Println("The absolute path of your dist directory ($DIST_DIR) contains a space character:")
+		ctx.Println()
+		ctx.Printf("%q\n", distDir)
+		ctx.Println()
+		ctx.Fatalln("Directory names containing spaces are not supported")
 	}
 
 	// Configure Java-related variables, including adding it to $PATH