Source & Tools: No EOL Whitespaces

End-of-line (EOL) whitespaces are verbose and increase diffs and
merge conflicts over time.

Cleaned them up for the `Source/`, `Examples/` and `Tools/` directory
with the following bash one-liner:

```bash
find . -type f -not -path './.git*'  \
  -exec sed -i 's/[[:blank:]]*$//' {} \;
```

Committed as generic user so git does not credit the many lines
to me:
```bash
GIT_AUTHOR_NAME="Tools" GIT_AUTHOR_EMAIL="warpx@lbl.gov"  \
  git commit
```

1 files changed, 3 insertions, 3 deletions

diff --git a/Source/FieldSolver/solve_E_nodal.F90 b/Source/FieldSolver/solve_E_nodal.F90
index e5ac50b2a..4ed9bb845 100644
--- a/Source/FieldSolver/solve_E_nodal.F90
+++ b/Source/FieldSolver/solve_E_nodal.F90
@@ -8,7 +8,7 @@ module warpx_ES_solve_E_nodal
 contains
 
 ! This routine computes the node-centered electric field given a node-centered phi.
-! The gradient is computed using 2nd-order centered differences. It assumes the 
+! The gradient is computed using 2nd-order centered differences. It assumes the
 ! Boundary conditions have already been set and that you have two rows of ghost cells
 ! for phi and one row of ghost cells for Ex, Ey, and Ez.
 ! Note that this routine includes the minus sign in E = - grad phi.
@@ -35,7 +35,7 @@ contains
     do k = lo(3)-1, hi(3)+1
        do j = lo(2)-1, hi(2)+1
           do i = lo(1)-1, hi(1)+1
-             
+
              Ex(i,j,k) = fac(1) * (phi(i-1,j,k) - phi(i+1,j,k))
              Ey(i,j,k) = fac(2) * (phi(i,j-1,k) - phi(i,j+1,k))
              Ez(i,j,k) = fac(3) * (phi(i,j,k-1) - phi(i,j,k+1))
@@ -61,7 +61,7 @@ contains
 
     do j = lo(2)-1, hi(2)+1
        do i = lo(1)-1, hi(1)+1
-             
+
           Ex(i,j) = fac(1) * (phi(i-1,j) - phi(i+1,j))
           Ey(i,j) = fac(2) * (phi(i,j-1) - phi(i,j+1))