Flash slides: using "managing" instead of "manipulating"

"managing" sounds more natural

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>

slides/sysdev-flash-filesystems/sysdev-flash-filesystems.tex

@@ -301,7 +301,7 @@ \section{Flash storage and filesystems}
 \end{frame}
 
 \begin{frame}[fragile]
-  \frametitle{U-Boot: manipulating NAND devices (1)}
+  \frametitle{U-Boot: managing NAND devices (1)}
   \begin{block}{}
   \tiny
   \begin{verbatim}
@@ -339,7 +339,7 @@ \section{Flash storage and filesystems}
 
 
 \begin{frame}[fragile]
-  \frametitle{U-Boot: manipulating NAND devices (2)}
+  \frametitle{U-Boot: managing NAND devices (2)}
   \begin{itemize}
   \item \code{nand info}\\
     Show available NAND devices and characteristics
@@ -367,7 +367,7 @@ \section{Flash storage and filesystems}
 \end{frame}
 
 \begin{frame}[fragile]
-  \frametitle{U-Boot: manipulating NAND devices (3)}
+  \frametitle{U-Boot: managing NAND devices (3)}
   \begin{itemize}
   \item \code{nand read[.option] <addr> <offset|partname> <size>}\\
     Read data from NAND
@@ -395,7 +395,7 @@ \section{Flash storage and filesystems}
 \end{frame}
 
 \begin{frame}[fragile]
-  \frametitle{U-Boot: manipulating NAND devices (4)}
+  \frametitle{U-Boot: managing NAND devices (4)}
   \begin{itemize}
   \item \code{nand erase.part <partname>}\\
     Erase a NAND partition
@@ -425,7 +425,7 @@ \section{Flash storage and filesystems}
 \end{frame}
 
 \begin{frame}[fragile]
-  \frametitle{U-Boot: manipulating NAND devices (5)}
+  \frametitle{U-Boot: managing NAND devices (5)}
   \begin{itemize}
   \item \code{nand bad}\\
     Shows bad blocks