Flash filesystems: minor improvements

- Fix typo
- Clarify when we are talking about raw flash devices
  (as opposed to flash based block storage)

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

slides/sysdev-block-filesystems/sysdev-block-filesystems.tex

@@ -3,10 +3,10 @@ \section{Block filesystems}
 \subsection{Block devices}
 
 \begin{frame}
-  \frametitle{Block vs. flash}
+  \frametitle{Block vs. raw flash}
   \begin{itemize}
   \item Storage devices are classified in two main types: {\bf block
-      devices} and {\bf flash devices}
+      devices} and {\bf raw flash devices}
     \begin{itemize}
     \item They are handled by different subsystems and different
       filesystems
@@ -180,7 +180,7 @@ \subsection{Available block filesystems}
 \end{frame}
 
 \begin{frame}
-  \frametitle{F2FS: filesystem for flash-based storage}
+  \frametitle{F2FS: filesystem for flash-based block storage}
   \url{https://en.wikipedia.org/wiki/F2FS}
   \begin{itemize}
   \item Filesystem that takes into account the characteristics of

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

@@ -156,7 +156,7 @@ \section{Flash storage and filesystems}
     \item \code{/dev/mtd1} is the second enumerated partition on the
       system (either from a single flash chip or from a different one).
     \item Note that the master MTD device (the device those partitions
-      belongs to) is not exposed in \code{/dev}
+      belong to) is not exposed in \code{/dev}
     \end{itemize}
   \end{itemize}
 \end{frame}