Make dev/mima runnable on Mac OS X.

Mac OS X's find is from the BSD variant that doesn't have -printf option.

Author: Reynold Xin <rxin@apache.org>

Closes #1953 from rxin/mima and squashes the following commits:

e284afe [Reynold Xin] Make dev/mima runnable on Mac OS X.

dev/mima

@@ -26,7 +26,9 @@ cd "$FWDIR"
 
 echo -e "q\n" | sbt/sbt oldDeps/update
 
-export SPARK_CLASSPATH=`find lib_managed \( -name '*spark*jar' -a -type f \) -printf "%p:" `
+export SPARK_CLASSPATH=`find lib_managed \( -name '*spark*jar' -a -type f \) | tr "\\n" ":"`
+echo "SPARK_CLASSPATH=$SPARK_CLASSPATH"
+
 ./bin/spark-class org.apache.spark.tools.GenerateMIMAIgnore
 echo -e "q\n" | sbt/sbt mima-report-binary-issues | grep -v -e "info.*Resolving"
 ret_val=$?