RFR (XXS): JDK-8019219 Typo in jdk/makefiles "default" targets

[Magnus Ihse Bursie]

Bug: https://bugs.openjdk.java.net/browse/JDK-8019219
The default target in CompileNativeLibraries.gmk and 
CompileLaunchers.gmk is spelled "defalt". This does not affect 
functionality.

Webrev: 
http://cr.openjdk.java.net/~ihse/JDK-8019219-correct-target-typo/webrev.01

/Magnus