[LyX/master] Replace outdated LASSERT

[Georg Baum]

commit c54b1368801d06ed740a24879721dfe599b2166a
Author: Georg Baum <b...@lyx.org>
Date:   Wed Mar 18 22:06:59 2015 +0100

    Replace outdated LASSERT
    
    The concept of rows and cols is no longer unique to mathed.
    Each inset decides itself whether it is grid like or not, so we should not
    interfere with this in the cursor slice.

diff --git a/src/CursorSlice.cpp b/src/CursorSlice.cpp
index e7ef90e..ae3686f 100644
--- a/src/CursorSlice.cpp
+++ b/src/CursorSlice.cpp
@@ -80,19 +80,15 @@ pit_type CursorSlice::lastpit() const
 
 CursorSlice::row_type CursorSlice::row() const
 {
-       // LASSERT: This should only ever be called from an InsetMath.
-       // Should we crash in release mode, though, or try to continue?
-       LASSERT(asInsetMath(), /**/);
-       return asInsetMath()->row(idx_);
+       LASSERT(inset_, return 0);
+       return inset_->row(idx_);
 }
 
 
 CursorSlice::col_type CursorSlice::col() const
 {
-       // LASSERT: This should only ever be called from an InsetMath.
-       // Should we crash in release mode, though, or try to continue?
-       LASSERT(asInsetMath(), /**/);
-       return asInsetMath()->col(idx_);
+       LASSERT(inset_, return 0);
+       return inset_->col(idx_);
 }