Remove slashes after %{buildroot}

%{_bindir} etc. already starts with a slash.
There is no need to put a slash after %{buildroot}.
(Except when pointing to the literal root of the buildroot and using just "%{buildroot}/".)

modules/ROOT/pages/_partials/proc_rpm_creating_an_rpm.adoc

@@ -61,8 +61,8 @@ A simple program to greet the user, Texas style.
 +
 [source]
 ----
-mkdir -p %{buildroot}/%{_bindir}
-install -p -m 755 %{SOURCE0} %{buildroot}/%{_bindir}
+mkdir -p %{buildroot}%{_bindir}
+install -p -m 755 %{SOURCE0} %{buildroot}%{_bindir}
 ----
 +
 NOTE: In this example, we use the following three macros: `%\{buildroot}`, `%\{_bindir}`, and `%\{SOURCE0}`. This method ignores the origin of the files and directories and focuses on the destination of the files. Without `%\{buildroot}` the files might install directly onto your development machine. This is not recommended, especially if you run as root. For more information on macros and `.spec` file entries, see xref:con_rpm_spec_file_overview[].

modules/ROOT/pages/create-hello-world-rpm.adoc

@@ -147,7 +147,7 @@ If the program uses GNU `info` files, you need to make sure the installation and
 * delete the `dir` file in `%install`:
 
 ----
-$ rm -f %{buildroot}/%{_infodir}/dir
+$ rm -f %{buildroot}%{_infodir}/dir
 ----
 
 * `Requires(post): info` and `Requires(preun): info`
@@ -202,7 +202,7 @@ make %{?_smp_mflags}
 %install
 %make_install
 %find_lang %{name}
-rm -f %{buildroot}/%{_infodir}/dir
+rm -f %{buildroot}%{_infodir}/dir
 
 %post
 /sbin/install-info %{_infodir}/%{name}.info %{_infodir}/dir || :