[DOCS] [MLLIB] Fixing broken link in MLlib Linear Methods documentation.

Just a small change: fixed a broken link in the MLlib Linear Methods documentation by removing a newline character between the link title and link address.

Author: Mike Dusenberry <dusenberrymw@gmail.com>

Closes #6340 from dusenberrymw/Fix_MLlib_Linear_Methods_link and squashes the following commits:

0a57818 [Mike Dusenberry] Fixing broken link in MLlib Linear Methods documentation.

docs/mllib-linear-methods.md

@@ -785,8 +785,7 @@ gradient descent (`stepSize`, `numIterations`, `miniBatchFraction`).  For each o
 all three possible regularizations (none, L1 or L2).
 
 For Logistic Regression, [L-BFGS](api/scala/index.html#org.apache.spark.mllib.optimization.LBFGS)
-version is implemented under [LogisticRegressionWithLBFGS]
-(api/scala/index.html#org.apache.spark.mllib.classification.LogisticRegressionWithLBFGS), and this
+version is implemented under [LogisticRegressionWithLBFGS](api/scala/index.html#org.apache.spark.mllib.classification.LogisticRegressionWithLBFGS), and this
 version supports both binary and multinomial Logistic Regression while SGD version only supports
 binary Logistic Regression. However, L-BFGS version doesn't support L1 regularization but SGD one
 supports L1 regularization. When L1 regularization is not required, L-BFGS version is strongly